1. Field of the Invention
The present invention relates to a fuel supply control device for an internal combustion engine, which calculates a manipulated variable of a fuel pump based on a detection value of a fuel pressure and output the calculated manipulated variable, and a fuel vapor processing method in the fuel supply control device.
2. Description of Related Art
In a technique disclosed in Japanese Laid-Open (Kokai) Patent Application Publication No. 9-151823, a current value driving a fuel pump is maximized until a rotating speed of the fuel pump reaches a first predetermined rotating speed during engine starting, and feedback control of the current value is performed such that a fuel pressure is matched with a target fuel pressure after the rotating speed of the fuel pump reaches the first predetermined rotating speed. Japanese Laid-Open (Kokai) Patent Application Publication No. 9-151823 also discloses the following fact. That is, when the rotating speed of the fuel pump exceeds a second rotating speed during the feedback control of the current value, a large quantity of air or fuel vapor is determined to be mixed in fuel piping, and the current value is maximized.
As described above, a sensor that detects the rotating speed of the fuel pump is required in the device that determines the presence or absence of the fuel vapor generation based on the rotating speed of the fuel pump, which results in a problem in that cost of the device increases.